Wireless communication systems are widely spread all over the world to provide various types of communication services such as voice or data. In general, the wireless communication system is a multiple access system capable of supporting communication with multiple users by sharing available system resources (e.g., bandwidth, transmission power, etc.). Examples of the multiple access system include a code division multiple access (CDMA) system, a frequency division multiple access (FDMA) system, a time division multiple access (TDMA) system, an orthogonal frequency division multiple access (OFDMA) system, a single carrier frequency division multiple access (SC-FDMA) system, etc.
While having almost the same complexity with the OFDMA, SC-FDMA has a lower peak-to-average power ratio (PAPR) due to a single carrier property. Since the low PAPR is advantageous for a user equipment (UE) in terms of transmission power efficiency, the SC-FDMA is adopted for uplink transmission in a 3rd generation partnership project (3GPP) long term evolution (LTE) as disclosed in section 5 of 3GPP TS 36.211 V8.2.0 (2008-03) “Technical Specification Group Radio Access Network; Evolved Universal Terrestrial Radio Access (E-UTRA); Physical channels and modulation (Release 8)”.
The wireless communication system generally uses one bandwidth for transmitting data. For example, a 2nd generation wireless communication system uses a bandwidth of 200 KHz˜1.25 MHz, and a 3rd generation wireless communication system uses a bandwidth of 5 MHz˜10 MHz. To support an increased transmission capacity, the next generation wireless communication system continues to extend its bandwidth to 20 MHz or higher. Accordingly, there has appeared a multi carrier system that defines a carrier having one bandwidth and a center frequency and uses a broadband to transmit and/or receive data through a plurality of carriers. Here, one or more carriers are used to support both a narrowband and a broadband. For example, on the assumption that one carrier corresponds to to a bandwidth of 5 MHz, four carriers can support the maximum bandwidth of 20 MHz.
In the SC-FDMA, efficiency of a power amplifier can be improved due to the low PAPR. However, it is not disclosed how to implement the SC-FDMA for maintaining the low PAPR in the multiple carrier system.